Feed mechanism for sewing machines



Sept. 20, 1938. H. J. LE VESCONTE ET AL 2,131,011

FEED MECHANISM FOR SEWING MACHINES 3 Sheets-Sheet 1 Filed Jan. 30, 1956 INVENTORS: mrold 11351655071355 & By Clamnu; B. Smzih 7 I ORNEYS.

WITNESSES: 4 6% Z/ Sept. 20, 1938. H. J. LE VESCONTE ET AL 2,131,011

FEED MECHANISM FOR SEWING MACHINES Filed Jan. 30, 1936 3 Sheets-Shet 2 FIG H 7121mm JLzWswnZe 13d TORNEYS.

H. J. LE VESCONTE ET AL 2,131,011

FEED MECHANISM FOR SEWING MACHINES Sept. 20,1938.

5 Sheets-Sheet 3 Filed Jan. 30, 1936 & I m \mwmmnm w mmmms E mmm m VV6 0 R mum w 5 T my B \%m \wm m6 m5 Patented Sept. 20, 1938 PATENT OFFICE FEED MECHANISM FOR SEWING MACHINES Harold J. Le Vesconte, Western Springs, and Clarence C. Smith, Chicago, 111., assignors to Union Special Machine Company, Chicago, 111., a co poration of Illinois Application January 30, 1936, Serial No. 81,472

v2i) Claims. (Cl. 112-215) This invention relates to feed mechanisms for sewing machines and the like, and particularly to what are known as four motion feeds especially adapted for lock stitch sewing machines wherein a rotary hook cooperates with the needle or needles in the formation of the stitches.

More specifically, the present invention has reference to sewing machine feed mechanisms of a type featured in a copending application Serial No. 51,992, filed jointly by Norman V. Christensen, Clarence C. Smith and George Sauer on November 29, 1935, which is characterized by having a single rotary actuator from whence both the feed and lift movements of the feed dog are obtained through the aid of interposed motion translating instrumentalities.

Our invention is directed toward refinements in feed mechanism of the kind specifically referred to which favor greater structural simplicity with attendant minimization of friction and momentum and attainment of a corresponding decrease in wear and vibration of the parts so that the sewing machine in which the mechanism is incorporated can be safely operated at higher speeds than heretofore possible; and which moreover favor greater compactness, with the parts so grouped in respect to the rotary hook so that the latter is left entirely unobstructed at the front of the sewing machine for convenience of ready access in removing and replacing the bobbins.

In connection with a feed mechanism having the above attributes, it is a further aim of our invention to provide for regulation of the stroke and the direction of feed without attendant change in the vertical or lift movements of the feed dog.

The foregoing, as well as other objects and attendant advantages, are all inherent in the feed mechanism.

Fig. BI is a fragmentary longitudinal sectional view taken as indicated by the arrows III-III in Fig. I.

Fig-IV is a transverse sectional view taken as indicated by the arrows IVIV in Fig. I.

Figs. V, VI, VII and VIII are detail sectional views corresponding to Fig. IV and showing the parts of the feed mechanism in different positions.

The horizontal bed plate or work support of the partly illustrated sewing machine is designated I, and as shown, has an integrally-formed pendant projection 2 whereof the portion 3 is made hollow to serve as a gear housing and is closed at the bottom by a removable plate 4. Journaled in a bearing bushing 5 (Fig. I) set into the pendant projection 2 of the work support I is a shaft 6 to the forward end of which is secured a rotary hook I of a suitable type capable of cooperating with the needle (not shown) of the machine to form lock stitches in the usual way. The hook shaft 6 is held against axial displacement Jointly by a collar 8 aflixed thereto at the left hand end and abutting the outer end of the bushing 5, and by a gear pinion 9 thereon engaging the inner end of said bushing within the gear housing 3. As shown in Fig. I, the pinion 9 meshes with a gear wheel i0 fast on a rotary shaft II which extends through the gear housing 2 and which is Journaled in bearing bushings l2 and I2 set respectively into the front and rear walls of said gear housing, the bushing .l 2 being secured by screws H. The shaft l I may be driven for example, in the manner disclosed in the copending application 670,186 hereinbefore referred to; and through the gears 9 and II rotary motion is imparted from said shaft to the hook shaft 6 at increased speed, said gears having in the present instance a one to two ratio. The bushing I2 is lubricated by oil introduced from above through a vertical oil hole IS in the work support I; (Fig. III) while the gears 9 and I0 and the bearing l3 are lubricated by oil splashed within the housing 3 which is normally kept filled to the level indicated in Fig. III.

- The feed mechanism with which the present invention is more especially concerned, comprises a feed dog it which operates above the rotary hook I, as shown in Fig. IV, and which is adjust ably secured to the forward end of a feed dog carrier or bar H by means of a screw i8. It is to be particularly noted from Figs. I, III and IV that the parts for actuating the feed dog l6 are all disposed at the side of the rotary hook I rearward of the direction of feed so that said hook is left unobstructed at the front of the machine for convenience of ready access in removing and replacing bobbins.

Fixed in a boss I! at the rear end of the feed bar I1 is a transverse wrist pin 20 whereof the opposite ends are engaged in aligned bosses 2| and 22 of a rocker 23. The fulcrum shaft 24 of the rocker 22 has its opposite ends Journaled in bushings 25 and 26 set into spaced pendant lugs 21 and 28 of the work support i. The rocker 23 receives its movement from a rotary actuator in the form of a small crank pin 23 on a head 30 at the end of the shaft I, through a horizontal pitman 3| comprising two telescoping components 32 and 33. The component 32 of the pitman 3| has a sleeve portion 34 which is intercepted by a yoke 35, and an end boss 36 in which is secured a transverse wrist pin 31 whereof the opposite ends are respectively engaged in another pair of spaced pivot bosses 38 and 39 of the rocker 23. At 40, the component 32 of the pitman 3| has pivotal connection with one end of a link 4| whereof the opposite end is in turn pivotally connected at 42 to the outer end of an arm 43 afiixed to a. regulating shaft 44 which is journaled in the pendant projection 3 of the work support By the elements thus far described, horizontal feed movements are imparted from the shaft H to the feed dog |6 to progressively advance the fabric in the machine in the direction of the arrow shown in Fig. IV, the stroke of said dog being adjustable or its action reversed through partial turning of the regulating shaft 44 in the manner fully set forth in Patent No. 2,035,508, granted on March 31, 1936, to George Sauer and Clarence C. Smith.

The means whereby the necessary vertical or lift movements are imparted in the feed dog l6 include a short oscillating shaft 45 which is axially aligned substantially with the shaft II and which is journaled in an inset bushing 46 of a bearing block 41 secured by a pair of screws 43 to the bottom of the work support I of the machine. At its outer or left hand end the oscillating shaft 45 has a diametrically-reduced eccentric portion or crank 43 to which is in turn adjustably secured, by means of a screw 50, an eccentric 5|. Embracing this eccentric 5| is a strap 52 having a pendant vertical link arm 53, whereof the lower end is pivotally connected at 54 to a downwardly and forwardly curved underreaching arm 55 of the feed bar ll. Integrally formed with, or secured to the right hand end of the rock shaft 45 is a downward arm 56 which is coupled by means of a horizontal link 15'! with a downward projection 58 on a split collar 53, which, by means of a screw 60, is clamped, with capacity for adjustment, to the shank 6| of the pitman component 33 within the opening of the yoke portion 35 of the other pitman component 32.

The oscillating shaft 45 is lubricated by oil led thereto by way of a downward duct 62 from a small reservoir 63 in the top of the bearing block 41, said reservoir being accessible for filling through a hole 64 in the work support I, see Figs. I and III. Extending laterally outward from the reservoir 63 is a tube 65 which overreaches the head 66 of the pitman component 33, said head having a boss 61 at the top with an elongated recess 63 and a communicating oil hole 63 (Figs. I

and III) leading down to the crank pin 23.

During each rotation of the crank 23, the boss 61 on the head 66 0f the pitman component 33 wipes against an oil conducting wick 10, (Fig. III) protruding from the downwardly beveled end of the tube 65 and leading from the reservoir 63 in the bearing block 41. In this way, adequate oil is supplied from the reservoir 63 to the crank 23 to keep the latter thoroughly lubricated at all times. 1

Considering the shaft II to be rotating clockwise as indicated by the arrows in Figs. V and VII, the operation of the feed mechanism, in-

sofar as the lift movements of the feed dog II are concerned, is as follows:

In Figs. IV and VI, the feed dog is elevated and positioned midway of its active or feed stroke to the left, with the crank 23 of the rotary shaft positioned as shown in Fig. V, and the crank 43 and the attached eccentric 5| of the oscillating shaft 45 positioned as shown in Fig. VI. Movement of the crank 23 from the position of Fig. V to that of Fig. VII is attended by bodily depression of the'pitman 3| as well as by incidental leftward movement of the pitman component 33 and the feed dog I 6 as indicated by the arrow on the latter in Fig. VI. As a consequence of the leftward movement of the pitman component 33, the oscillating shaft 45 is swung clockwise from the position of Fig. V to the p sition of Fig. VII, whereby, through the crank 43, the attached eccentric 5| and the strap link 53, the feed dog 6 is lowered to the position of Fig. VIII with its teeth below the top of the work support During rotation of the shaft through another quadrant from the position of Fig. VII, the pitman 3| is bodily elevated while the component 33 continues leftward, with incidental further clockwise movement of the oscillating shaft 45 so that the feed dog I6 is fully lowered by the time it reaches the midpositlon of its rightward or idling return stroke. half rotation of the shaft II to complete the feed cycle, reversal of the foregoing takes place, that is to say, the oscillating shaft 45 and the eccentric 5| thereon are swung anticlockwise with resultant elevation of the feed dog |6 through the medium of the strap link 53 and advance of said feed dog to the position of Fig. VI on its leftward or active stroke. Thus, through the pitman 3|, the link 51, the arm 56, the oscillating shaft 45, the eccentric 5| and the strap link 53, the horizontal component of movement of the crank 29 on the rotary shaft H is translated into up and down or lift movements of the feed dog ll.

Since the link 5'! is connected, through the split collar 53, to the pitman component 33 direct-connected to the crank 23 on the rotary shaft the lift movements of the feed dog will not be affected when adjustments are made in the feed stroke or the action of said dog reversed by means of the regulating'shaft 44. A further advantage of our improved feed mechanism is that the timing of the lift movements of the dog l6 may be changed in respect to the feed movements thereof by adjusting the clamp collar 53 along the shank 6| of the pitman component 33; and if a change should be desired or required in the lift movement, this may be effected simply During the remaining by rotatively adjusting the eccentric 5| about the crank 43on the oscillating shaft 45.

From the foregoing it will be realized that our improved feed mechanism is simple and comipact with its parts so interconnected as to insure operation at high speeds, and so arranged as to leave the rotary hook conveniently accessible for bobbin changing.

We do not of course consider ourselves limited to the precise details of construction and arrangement herein shown and described by way of example, since these can be considerably varied without departing from the spirit of our invention as defined in the appended claims.

Having thus described our invention, we claim:

1. Feed mechanism for sewing machines and the like comprising a feed dog and a carrier therefor; and means forimparting feed and lift movements to the feed dog, including a rocker.

a rotary actuator, a pitman connecting the rocker with the rotary actuator, an oscillating shaft,

a link connecting an arm on said shaft with the pitman, and a link connectinga crank on said shaft with an underreaching arm on the feed dog carrier.

therefor: and means for imparting feed and lift movements to the feed dog including a rocker,-

a rotating actuator,- a pitman connecting the rocker with the rotary actuator, an oscillating shaft, a link connecting an arm on the shaft with the pitman, aneccentric rotatably adjustable about a crank on said shaft, and a strap link connecting the eccentric with the feed dog carrier.

3. Feed mechanism for sewing machines and the like comprising a feed dog and a carrier therefor; and means for imparting feed and lift movements to the feed dog including a rocker, a rotary shaft, a pitman connecting the rocker with a crank on said rotary shaft, an oscillating shaft substantially aligned axially with the rotating shaft; a horizontal link connecting an arm on said oscillating shaft with the pitman, and a vertical link connecting a crank on said oscillating shaft with an underreaching arm of the feed-dog carrier.

4. Feed mechanism for sewing machines and the like comprising a feed dog and a carrier therefor; and means for imparting feed and lift movements to the feed dog including a rocker, a rotary shaft, a pitman connecting the rocker with a crank on said rotary shaft, an oscillating shaft substantially aligned axially with the rotating shaft, a link connecting an arm on said oscillating shaft with the pitman, an eccentric rotatably adjustable about a crank on the oscillating shaft, and a vertical strap link connecting the eccentric with the feed dog carrier.

5. Feed mechanism for sewing machines and the like comprising a feed dog and a carrier therefor; and means for imparting feed and lift movements to the feed .dog including a rocker, a rotary actuator, a pitman with telescoping components connecting the rocker with the rotary actuator, a regulating shaft for adjusting the feed stroke of the dog, a link connecting an arm on said regulating shaft with that component of the pitman directly connected to the rocker, an oscillating shaft, 9, link connecting an arm on said oscillating shaft with that component of the pitman directly connected to the rotary actuator, and a link connecting a crank on the oscillating shaft with an underreaching arm of the feed dog carrier.

6. Feed mechanism for sewing machines and the like comprising a feed dog and a carrier therefor; and means for imparting feed and lift movements to the feed dog including a rocker,

a rotary actuator, a pitman with telescoping components connecting the rocker with the rotary actuator, a regulating shaft for adjusting the feed stroke of the dog, a link connecting an arm on said regulating shaft with that component of the pitman directly connected to the rocker, an oscillating shaft, a link connecting an arm on the oscillating shaft with that component of the pitman directly connected to the rotary actuator, an eccentric rotatably adjustable about a crank on the oscillating shaft, and a strap link connecting the eccentric with the feed dog carrier.

'7. Feed mechanism for sewing machines and the like comprising a feed dog and a carrier therefor; and means for imparting feed and lift movements to the feed dogincluding a rocker,

a rotary shaft, a pitman with telescoping com-,

ponents connecting the rocker with a crank on the rotary shaft, a regulating shaft for adjusting 1 the feed stroke of the dog, a link connecting an arm on said regulating shaft with that component of the pitman directly connected to the rocker, an oscillating 'shaft in substantial alignment axially with the rotary shaft, a link connecting an arm on said oscillating shaft with that component of the pitman directly connected to the rotary actuator, and a link connecting a crank on the oscillating shaft-.with an underreaching arm of the feed dog carrier.

8. Feed mechanism for sewing machines and the like comprising a feed dog and a carrier therefor; and means for imparting feed and lift movements to the feed dog including a rocker, a rotary actuator, a pitman with telescoping components connecting the rockerwith the rotary actuator, a regulating shaft for adjusting "the feed stroke of the dog, a link connecting ,an arm on said regulating shaft with that component of the pitman directly connected to the rocker, an oscillating shaft, a horizontal link with one'end thereof connected to an arm on said oscillating shaft and with the other end thereof connected with capacity for adjustment, to that component of the pitman directly connected to the rotary actuator, and a link connecting a crank on the oscillating shaft with an underreaching arm of the feed dog can'ier.

-9. Feed mechanism for sewing machines and the like comprising a feed dog and a carrier therefor; and means for imparting feed and lift movements'to the feed dog including a rocker, a rotary actuator, a pitman with telescoping components connecting the rocker with the rotary actuator, a regulating shaft for adjusting the feed stroke of the dog, a link connecting an arm on said regulating shaft with that component of the pitman directly connected to the rocker, an oscillating shaft, a link with one end thereof connected to an arm on said oscillating shaft and the other end thereof connected with capacity for adjustment to that component of the pitman directly engaging the rotary actuator, an eccentric rotatably adjustable about a crank on the oscillating shaft, and a strap link connecting the eccentric with an underreaching arm of the feed 'dog carrier.

10. Feed mechanism for rotary hook sewing v wholly at one side of said rotary hook, a rotary shaft, and a single actuating member on said shaft from which the feed dog carrier receives a four-motion feeding movement.

11. Feed mechanism for rotary-hook sewing machines comprising a feed dog operating above the rotary hook, a carrier for the feed dog disposed wholly at one side of said hook, a rotary shaft, a single actuating member on said shaft from which rising and falling movements, as well as back and forth movements are imparted to said carrier, and means whereby the length or direction of the feeding movements of said dog may be varied.

12. Feed mechanism for rotary hook sewing machines comprising a feed dog operating above the rotary hook, a carrier for the feed dog disposed wholly at one side of said hook, a rotary shaft, a single actuating member on said shaft from which rising and falling movements as well as back and forth movements are imparted to said carrier, and means whereby the length of the feed stroke of the dog may be varied and whereby the feeding action of said dog may be reversed without affection of its rising and falling movements.

13. Feed mechanism for rotary hook sewing machines comprising a feed dog; and means for imparting feed and lift movements to the feed. dog disposed entirely to one side of the rotary hook, said means including a rocker, a rotary actuator,

a carrier for the feed dog pivotally connected to the rocker, a horizontal pitman connecting the rocker with the rotary actuator, an oscillating shaft, a horizontal link connecting an arm on said oscillating shaft with the pitman aforesaid, and

oscillating shaft, a horizontal link connecting an arm on said oscillating shaft with the pitman, an eccentric rotatably adjustable about a crank pin on said oscillating shaft, and a vertical strap link. connecting said. eccentric with an underreaching arm on the feed dog carrier.

15. Feed mechanism for rotary hook sewing machines comprising a feed dog; and means for imparting feed and lift movements to the feed dog disposed entirely to one side of the rotary hook, said means including a rocker, a rotary shaft ex tendingparallel with the shaft of the rotary hook, a carrier for the feed dog pivotally connected to the rocker, a horizontal, pitman connecting the rocker with a crank on said rotary shaft an oscillatingshaft substantially aligned axially with the rotary shaft, a horizontal link connecting an arm on said oscillating shaft with the pitman, and a vertical link connecting a crank on the oscillating shaft with an underreaching arm on the feed dog carrier.

18. Feed mechanism for rotary hook sewing machines comprising a feed dog; and means for imparting feed and lift movements to the feed dog disposed entirely to one side of the rotary hook, said means including a rocker, a rotary actuator, a carrier for the feed dog pivotally connected to the rocker, a horizontal pitman with telescoping components connecting the rocker with the rotary actuator, a regulating shaft for adjusting the feed stroke of the dog; a link connecting an arm on the regulating shaft with that component of the pitman directly connected to the rocker, an oscillating shaft, a horizontal link connecting an arm on said oscillating shaft with that component of the pitman directly connected ,to the rotary actuator, a crank on the oscillating shaft, and a vertical link connecting said crank with an underreaehing arm onthe feed dog car rier.

11. rue mechanism for rotary machinescomprisingafeeddomandmesnsfor" shaft for "adjusting the feed stroke of the link connecting an arm on said regulating shaft with that component of the pitman directly connected to the rocker. an oscillating shaft: is horizontal link connecting anarmonsaidoscillatingshaftwith that component of the pitman directly connected to the rotary actuator, a crank on the oscillating shaft, an eccentric rotatsblr ndinstabie on the crank, and a vertical strap link said' eccentric with an under-reaching arm on the feed dog carrier.

18. Feed mechanism for rotary hook sewing machines comprising a feed dog; and means for imparting feed and lift movements to the feed dog disposed entirely to one side of the rotary hook, said means including a rocker, a rotary shaft parallel with the shaft of the rotary hook, a carrier for the feed dog pivotally connected to the rocker, a horizontal pitman with telescoping components connecting the rocker with. a, crank on the rotary shaft, a regulating shaft for adjusting the feed stroke of the dog, a link connecting an arm on the regulating shaft with that component of the pitman directly with the rocker, an oscillating shaft tially aligned axially with the rotary shaft, a horizontal link connecting an arm on said oscillating shaft with that component of the pitrnan directly connected to the crank, and a vertical link connecting a. crank on the oscillating shaft with an underreaching arm on the feed dog carrier.

19. Feeding mechanism for sewing machines comprising a feed dog: means for imposing fourmotion movements thereto including a rotary shaft. an oscillating member rearward of the point of stitch formation in the direction of feeding and operatively connected to the rotary shaft from which the dog receives its horizontal back and forth movements, and a second ting member operatively connected with the shaft and substantially axially aligned therewith from which the dog receives its rising and falling movements.

20. Feeding mechanism for sewing machines comprising a feed dog; means for imparting fourmotion feed movements including a rotary shaft,

an oscillating member rearward of the point of stitch formation in the direction of f from which the feed dog receives it horizontal back and forth movements, a second member substantially axially aligned with the rotary shaft from which the dog receives its rising and falling movements. and a single actuator on said shaft to which said oscillating are operatively connected.

HAROIDLIEVECOR'IE. CIARENCEC.SII1T H.

movementstothefeed 

